JPH09137091A - Water-based magenta ink for recording and ink-jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the above ink having excellent sharpness, color tone, liquid stability, fast drying property, printed letter quality, etc., and produced by using a specific magenta dye in combination with a specific amount of a polyhydric alcohol alkyl ether having a vapor pressure lower than a specified level. SOLUTION: This magenta ink contains C.I. Acid Red 52 as a magenta ink and 5-15wt.% of a polyhydric alcohol alkyl ether having a vapor pressure of <=0.1mmHg at 20 deg.C (e.g., diethylene glycol monobutyl ether having a vapor pressure of 0.01mmHg under the above condition). The solvent to be used in the ink composition is preferably a mixture of water (preferably deionized water) and a water-soluble organic solvent. The content of the water-soluble organic solvent in the ink composition is preferably 10-50 wt.% and that of water is preferably 20-70wt.% based on the total ink composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous recording magenta ink and an ink jet recording method.

[0002]

2. Description of the Related Art Ink jet recording methods include various ink ejection methods (for example, an electrostatic suction method, a method in which a piezoelectric element is used to mechanically vibrate or displace ink, and air bubbles are generated by heating ink at that time. The ink droplets are formed by a method utilizing the pressure generated in the recording medium), and a part or all of them are attached to a recording material such as paper for recording.

As an ink composition used in such an ink jet recording system, there is known an ink composition obtained by dissolving or dispersing various water-soluble dyes or pigments in water or a liquid medium comprising water and a water-soluble organic solvent. And used. Such ink compositions are required to have optimal performance characteristics for that purpose. For example, sedimentation or aggregation does not occur even if the ink jet printer is not used for a long period of time, clogging does not occur at the tip of the ink jet printer head and in the ink flow path, and the printing quality is good. Among them, the most demanded performance is when the ink is used for recording, when the recording is interrupted, and when the recording is not performed for a long period of time, the head of the inkjet printer head or the ink in the ink flow path Recording characteristics, liquid stability that does not cause clogging and sedimentation, and stable ejection, and quick-drying that the recording material dries quickly and does not bleed even if rubbed with a finger etc., recorded characters and ruled lines There is no beard-like bleeding (feathering), etc., and the mixture of colors in the area where different colors are adjacent (bleeding)
There is no odor and the print quality is a clear image, and the ink itself has a low odor.

When a dye and a pigment are compared, the pigment is not dissolved in the ink medium but is dispersed, but the dye is completely dissolved in the ink medium, so that the dye ink composition is compared with the pigment ink composition. Therefore, clogging hardly occurs at the tip of the ink jet printer head and in the ink flow path, and the liquid stability is far superior. For this reason, inks for ink jet printers often have a dye ink composition. Among such dye ink compositions, water-based dye ink compositions in which dyes are dissolved in water are predominant, and water-soluble dyes having various chemical structures are used as mixed solvents of water and / or water-soluble organic solvents. Those which are dissolved and to which various additives are added as needed are currently mainly used.

[0005]

However, even in the aqueous dye ink composition produced as described above, the liquid stability,
It is difficult to satisfy all of quick drying, print quality characteristics, safety, and low odor, and various improvements have been studied, but
Not enough yet. Further, the sharpness and color tone of the recorded matter change depending on the type of dye used, but the water resistance is poor for an ink composition using an acid dye which gives a particularly clear image. Further, among the acid dyes, the color index number Acid Red 52 gives a magenta color having a vivid and good color tone, but has particularly a poor water resistance, which has a serious problem.

The present invention has been made in order to solve the above-mentioned problems, and simultaneously satisfies sharpness, good color tone, liquid stability, fast drying property, print quality characteristics, low odor and water resistance. An object of the present invention is to provide a magenta ink composition and an inkjet recording method that does not cause clogging.

[0007]

To achieve this object, the recording water-based magenta ink according to claim 1 uses a color index number Acid Red 52 as a magenta dye and further has a vapor pressure at 20 ° C. 0.
5 polyhydric alcohol alkyl ether of 1 mmHg or less
It is characterized by containing ~ 15% by weight.

An ink jet recording method for recording using the recording water-based magenta ink according to claim 2 is
A color water-based recording magenta ink containing 5 to 15% by weight of a polyhydric alcohol alkyl ether having a vapor pressure at 20 ° C. of 0.1 mmHg or less is used. And

In the present invention having the above constitution, the color index number Acid Red 52 is used as the magenta dye, and the vapor pressure at 20 ° C. is 0.1 m.
5 to 1 of polyhydric alcohol alkyl ether of mHg or less
Since it contains 5% by weight, it has clearness, color tone, liquid stability,
An ink jet recording method is achieved which has good quick-drying properties, print quality characteristics, water resistance, low odor and does not cause clogging.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

The dye used in the present invention includes:
Limited to Color Index Number Acid Red 52, which is a water-soluble acid dye. This dye has a more vivid color than other acid dyes and direct dyes, and has a good color tone as magenta. Generally, a water-soluble dye is used in a ratio of about 0.1 to 10% by weight in a conventional ink composition, but in the present invention, about 0.1 to 10% by weight is used.
Even with 1 to 5% by weight, sufficient color depth and vividness of the recorded matter can be obtained.

2 used in the ink composition of the present invention
The polyhydric alcohol alkyl ether having a vapor pressure at 0 ° C. of 0.1 mmHg or less improves the quick-drying property of the ink on the recording paper by effectively increasing the ink permeation speed into the recording paper, and A material that prevents bleeding due to slow drying property and is less likely to cause feathering due to permeation is preferably used. The polyhydric alcohol alkyl ether also has the function of improving the water resistance of the color index number Acid Red 52.

The reason why the polyhydric alcohol alkyl ether improves the water resistance of the color index number Acid Red 52 is not clear, but since the solubility of the color index number acid red 52 in the polyhydric alcohol alkyl ether is low, When water evaporates after the ink has penetrated the recording paper, the color index number Acid Red 52 is deposited as a solid due to the increase in the proportion of the polyhydric alcohol alkyl ether in the remaining ink, and the color index number Acid Red 52 is deposited on the recording paper. It is expected that this is due to sticking.

Specific examples of the polyhydric alcohol alkyl ether include diethylene glycol monomethyl ether (0.1 mmHg), diethylene glycol monobutyl ether (0.01 mmHg) and diethylene glycol monoisobutyl ether (0.01 mmHg).
g), dipropylene glycol monomethyl ether (0.06 mmHg), dipropylene glycol monopropyl ether (0.02 mmHg), dipropylene glycol monoisopropyl ether (0.05 mmHg
g), dipropylene glycol monobutyl ether (0.05 mmHg), triethylene glycol monomethyl ether (less than 0.01 mmHg), triethylene glycol monobutyl ether (less than 0.01 mmHg), tripropylene glycol monomethyl ether (0.02 mmHg), tri Examples include propylene glycol monobutyl ether (less than 0.01 mmHg). However, the value in () shows the vapor pressure at 20 ° C.

A general polyhydric alcohol alkyl ether has a peculiar odor and its vapor pressure is 0.
If the ink having a viscosity higher than 1 mmHg is used, the ink itself becomes highly odorous, which is a serious problem for use in general offices and homes. However, the polyhydric alcohol alkyl ether exemplified above has a low vapor pressure at 20 ° C. of 0.1 mmHg or less, has low odor even when used in ink, and does not have the above-mentioned problems.

The content of the polyhydric alcohol alkyl ether in the ink is 5 to 1 by weight% with respect to the total amount of the ink.
5% by weight is preferred. If the amount is less than 5% by weight, the rate of penetration of the ink into the recording paper is slow and problems often occur in the drying time and bleeding. On the other hand, if it exceeds 15% by weight, the penetration of the ink into the recording paper becomes severe, the ink reaches the back of the recording paper, and a problem often occurs in feathering.

The solvent used in the ink composition of the present invention is water or a mixed solvent of water and a water-soluble organic solvent,
Particularly preferred is a mixed solvent of water and a water-soluble organic solvent, which contains a polyhydric alcohol having an ink drying prevention effect as a water-soluble organic solvent. Further, as the water, it is desirable to use deionized water instead of general water containing various ions.

As the water-soluble organic solvent used by mixing with water, for example, methyl alcohol, ethyl alcohol,
n-propyl alcohol, isopropyl alcohol, n
-Butyl alcohol, sec-butyl alcohol, te
lower alcohols such as rt-butyl alcohol, amides such as dimethylformamide and dimethylacetamide,
Acetone, ketones such as diacetone alcohol or keto alcohols, tetrahydrofuran, ethers such as dioxane, polyethylene glycol, polyalkylene glycols such as polypropylene glycol, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol,
Dipropylene glycol, tripropylene glycol,
Examples thereof include alkylene glycols such as thiodiglycol and hexylene glycol, glycerin, 2-pyrrolidone, N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone.

The content of the water-soluble organic solvent in the ink composition is generally 0% by weight based on the total weight of the ink.
The range is from 95 to 95% by weight, preferably from 10 to 80% by weight, more preferably from 10 to 50% by weight.

The water content at this time is determined in a wide range depending on the kind of the solvent component, its composition, or the desired characteristics of the ink, but is generally 10 to the total weight of the ink. The range is 95% by weight, preferably 10 to 70% by weight, more preferably 20 to 70% by weight.

The basic composition of the ink composition of the present invention is as described above, but various other conventionally known additives such as dispersants, surfactants, viscosity modifiers, surface tension modifiers, pH modifiers and anti-reflective agents. A fungicide or the like can be added if necessary. For example, polyvinyl alcohol, celluloses, viscosity modifiers such as water-soluble resins, cations, anions,
Nonionic surfactants, pH adjusters such as diethanolamine and triethanolamine. When an ink composition used in an inkjet recording method of charging a recording liquid is prepared, a resistivity adjusting agent such as an inorganic salt such as ammonium chloride is added.

Next, examples and comparative examples of the present invention will be described, but the present invention is not limited thereto.

Example 1 Pure water (73 parts by weight), color index number Acid Red 52 (2 parts by weight), ethylene glycol (20 parts by weight), diethylene glycol monobutyl ether (5 parts by weight, vapor pressure at 20 ° C.) Is 0.01 mmH
g) was added, and the mixture was stirred for 30 minutes and then filtered through a membrane filter having a pore size of 0.7 μm to obtain a magenta ink composition.

Regarding this ink composition, the following (1) to
When the examination of (8) was carried out, good results were obtained in all cases.

(1) Long-term stability: No precipitation of insoluble matter was observed even after the ink composition was sealed in a heat-resistant glass bottle and stored at −30 ° C. and 60 ° C. for 6 months, and the physical properties and color tone of the liquid were almost the same. There was no change.

(2) Discharge stability; JP-A-2-15035
Using a shear mode type ink jet head disclosed in Japanese Patent Application Publication No. 5 (1993) -105, continuous ejection was performed for 24 hours at each of the ambient temperatures of 5 ° C., 20 ° C., and 40 ° C. The quality was recorded.

(3) Discharge response: JP-A-2-15035
The intermittent ejection for one minute and the ejection after standing for two months were examined using a shear mode type ink jet head disclosed in Japanese Patent Application Publication No. 5 (1993) -105, and in each case, the tip of the head of the ink jet printer and the ink flow path were examined. The recording was stable and uniform without clogging.

(4) Quality of recorded image: The image recorded on the recording material shown below had a high density and was clear, and a magenta color having a good color tone was obtained.

Recording material: Xerox high-quality paper "Xerox 4024" Hokuetsu Paper Co., Ltd. high-quality paper "Seven Star" Honshu Paper Co., Ltd. medium-quality paper "White Peony" Toyo Roshi Co., Ltd. non-size paper "Toyo Filter Paper No. 4".

(5) Fixability and quick-drying property on various recording materials: After 5 seconds of recording on the recording material shown in (4) above, the print part was rubbed with a finger to determine the presence or absence of image shift and bleeding. ,
In all cases, there was no image shift or bleeding, and excellent fixability was exhibited.

(6) Print quality characteristics of various recording materials: When the print quality characteristics of characters and images recorded on the recording material shown in (4) above were confirmed, both feathering and bleeding were good. It was

(7) Water resistance: The recorded matter obtained in (4) above was dipped in water for 1 minute, taken out and dried, and then the recorded matter was observed. I was able to confirm clearly.

(8) Low odor: 100 g of the ink composition was weighed in a 100 ml glass beaker and the odor was confirmed. As a result, it was almost odorless.

Example 2 In Example 1, instead of diethylene glycol monobutyl ether, triethylene glycol monobutyl ether (vapor pressure at 20 ° C. is less than 0.01 mmHg)
Was used to prepare a magenta ink composition with an addition amount of 10% by weight, and the same experiment was carried out. As a result, excellent results were obtained in the same manner as in Example 1.

Example 3 In Example 1, dipropylene glycol monobutyl ether was replaced with dipropylene glycol monomethyl ether (vapor pressure at 20 ° C. was 0.06 mmHg), and the addition amount was 7% by weight to prepare a magenta ink composition. When they were manufactured and tested in the same manner, they all showed excellent results as in Example 1.

Example 4 In Example 1, tripropylene glycol monomethyl ether (vapor pressure at 20 ° C. was 0.02 mmHg) was used in place of diethylene glycol monobutyl ether, and the addition amount was 12% by weight to prepare a magenta ink composition. When they were manufactured and tested in the same manner, they all showed excellent results as in Example 1.

Example 5 In Example 1, instead of diethylene glycol monobutyl ether, tripropylene glycol monobutyl ether (vapor pressure at 20 ° C. is less than 0.01 mmHg)
Was used to prepare a magenta ink composition with an addition amount of 15% by weight, and the same experiment was carried out. As a result, excellent results were obtained in the same manner as in Example 1.

Comparative Example 1 In Example 1, a magenta ink composition was prepared without using diethylene glycol monobutyl ether, and the same experiment was carried out. As a result, in (5), the penetration was slow and the result was bleeding by rubbing with a finger. Further, in (6), the feathering was good, but severe bleeding was observed. Further, in (7), the water resistance was poor, that is, the color fading and bleeding were severe, and characters and images could not be confirmed.

Comparative Example 2 A magenta ink composition was prepared in the same manner as in Example 1 except that ethylene glycol monomethyl ether (vapor pressure at 20 ° C. was 6.2 mmHg) was used instead of diethylene glycol monobutyl ether. ,
Good results were obtained in (1) to (7),
In (8), an unbearable irritating odor was confirmed.

Comparative Example 3 A magenta ink composition was prepared in the same manner as in Example 1 except that 1 part by weight of diethylene glycol monobutyl ether was used and the same experiment was carried out. As a result, (1) to (4), (7),
In (8), good results were obtained, but in (5), the penetration of the ink was slow, and the image was blurred when rubbed with a finger. Further, in (6), the feathering was good, but severe bleeding was observed.
Further, in (7), the water resistance was poor, and characters and images could not be clearly confirmed.

Comparative Example 4 A magenta ink composition was prepared in the same manner as in Example 1 except that 30 parts by weight of diethylene glycol monobutyl ether was used, and the same experiment was conducted. As a result, (1) to (5), (7),
Good results were obtained in (8), but bleeding was good in (6), but severe feathering was observed. Also, when the back surface of the recorded matter was checked, the ink reached the back surface.

The ink compositions of Examples 1 to 5 were excellent in jetting, good in sharpness, color tone, liquid stability, quick drying property, print quality property, water resistance, and low odor. Also used Color Index Number Acid Red 52 as a magenta dye, and further contained 5 to 15% by weight of a polyhydric alcohol alkyl ether having a vapor pressure at 20 ° C. of 0.1 mmHg or less.

On the other hand, in Comparative Examples 1 to 4 in which the print quality characteristics and the water resistance were poor, and the odor was irritating, none of the above conditions was satisfied.

[0044]

As is clear from the above description, the recording water-based magenta ink according to claim 1 uses the color index number Acid Red 52 as the magenta dye and has a vapor pressure of 20.degree. 1 mm
5 to 15 polyhydric alcohol alkyl ether below Hg
Since it contains wt%, it has good jetting, sharpness,
A water-based magenta ink for recording having excellent color tone, liquid stability, quick drying property, print quality property, water resistance, and low odor is produced.

An ink jet recording method for recording using the recording water-based magenta ink according to claim 2 is
Since a color index number Acid Red 52 is used as a magenta dye, and a recording water-based magenta ink containing 5 to 15% by weight of a polyhydric alcohol alkyl ether having a vapor pressure at 20 ° C. of 0.1 mmHg or less is used. , Good injection, low odor, sharpness, color tone, liquid stability, quick drying, print quality characteristics,
An ink jet recording method having excellent water resistance is achieved.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahito Kato 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-shi Inside (72) Inventor Shunichi Higashiyama 15-1 Naoshiro-cho, Mizuho-ku, Nagoya-city Inside the corporation

Claims (2)

[Claims] 1. A water-based magenta ink for recording, which uses a color index number Acid Red 52 as a magenta dye and further contains 5 to 15% by weight of a polyhydric alcohol alkyl ether having a vapor pressure at 20 ° C. of 0.1 mmHg or less. A water-based magenta ink for recording which is characterized by: 2. An ink jet recording method for recording using a recording aqueous magenta ink, wherein a polyhydric alcohol having a color index number Acid Red 52 as a magenta dye and a vapor pressure at 20 ° C. of 0.1 mmHg or less is used. An inkjet recording method comprising using a recording aqueous magenta ink containing 5 to 15% by weight of an alkyl ether.